Cathode-ray tube processing apparatus



March 29, 1960 J. J. OCALLAGHAN CATHODE-RAY TUBE PROCESSING APPARATUS Filed July 18, 1956 CA' I'HODE-RAY TUBE PROCESSING APPARATUS Jerome J. OCallaghan, Skokie, Ill., assignor to The Rauland Corporation, a corporation of Illinois Application July 1s, 1956, Serial No. 598,583

' 3 Claims. or. 134-169) This invention relates generally to tube and bulb washing machines and more specifically to apparatus for washing the internal surfaces of cathode-ray tube envelopes.

It is well known that before the luminescent coating may successfully be' applied to the internal face of a cathode-ray tube, the surface must first be cleansed and rendered perfectly free from all extraneous substances. This, of course, necessitates many successive steps of washing operation using a strong solution wash, for it is not at all uncommon in the production of cathode-ray tubes that 50% of the tube rejections after screening be due to improper washing. A typical example of a complete tube washing operation may consist of first subjecting the internal face of the tube envelope to three successive washing operations using a strong solution of hydrofluoric acid, followed by two successive washes using caustic or sodium hydroxide, then two successive rinsing steps using recirculated deionized water and finally two successive rinsing steps using pure deionized water, thus making a sum total of nine washing operations performed on the internal face of each cathode-ray tube envelope.

The use of such corrosive solutions as hydrofluoric acid and sodium hydroxide presents many problems due to the inability of many metals and materials to withstand the inherent corrosive nature of these solutions.

Again, in order to insure the'most eflicient washing operation, it is desirable that only the face plate of the cathode-ray tube be subjected to a high speed jet of washing solution. The reason for this is, that asa high speed jetof washing solution is directed toward the face plate from a source external of the tube envelope, drainage of the solution from the envelope through the neck thereof is found to impede the incoming jet of washing solution, thereby causing considerable turbulence of the incoming jet so that its maximum force is decreased; additionally, the jet of solution is deflected from its normal course away from the face, therefore decreasing the efliciency of the washing operation.

A further difliculty encountered with the use of a highspeed jet of washing solution resides in the fact that minute particles of glass from the glass face plate are dislodged and built up in the form of a sedimentation of highly abrasive material which of course is a constant hazard to exposed moving parts. I

Therefore, one of the principal objects of this invention is to devise a new and improved bulb washing apparatus which subjects only the internal face of the cathode-ray tube envelope to a high speed jet of wash solution which is immediately drained from the tube envelope without causing interference with the incoming jet of wash solution.

Another object of this invention is to devise a new and improved bulb washing machine which is capable of withstanding subjection to highly corrosive solutions and abrasive materials.

Another object of this invention is to devise a new and improved bulb washing machine which is highly eflicient in its cleansing ability and is capable of performing all the necessary successive steps of washing operation in a minimum of time under the control of an unskilled operator.

'lt is a corollary object of this invention to devise a.

new and improved bulb washing apparatus which is readily adaptable to incorporation in a multi-station auto-f maticbulb washing machine, utilized in the mass production of cathode-ray tubes, in which the internal sur-. faces of a plurality of successive cathode-ray tube envelopes are subjected to all of the successive steps of a complete washing cycle in a completely automatic manner so that the services of the operator need only be that ofloading and unloading the envelopes from the machine.

In accordance with the invention, apparatus for washing the internal surface of a cathode-ray tube envelope comprises means for supporting the envelope in an inthe supporting means, is provided for reciprocatingthe second conduit means to selectively engage and disengage one end of the second conduit means with the supported end of the first conduit means. Further means are provided for injecting a washing solution under pressure through the second conduit means, and fluid pressure means is operatively connected to the actuating means.

Finally, valve means is provided for selectively controlling the fluid pressure means and the injection means to actuate the injection means only upon operation of the actuating means to effect engagement of the first and second conduit means. A I

The features of the present invention which are be- A lieved to be novel are set forth with particularity in the appended claims. The organization and manner of operation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, in which the single figure is a side view, partly schematic and in section, depicting apparatus constructed in accordance with a preferred embodiment of the present invention. 7

It is to be noted at the outset that no attempt has been made to construct the drawing to scale as sizes, dimensions, and proportionalities are not required for a complete understanding of the principles of the invention.

With reference to the drawing, an actuating mechanismindicated generally by the reference numeral 10 is operatively connectedto a support structure 11 by any 'suitable'meansand consists essentially of a vertically extending stationary cylindrical bearing support member 12 having an axially movable conduit member 13 slid ably mounted therein and supported by tubular sleeve bearings 14 and 15 interposed between members 12 and j;

13." Upper and lower circular plate members 16 and 17 respectively are integrally connected to conduit 13 by any suitable fluid-tight bonding means as by welding or f the like. An upper expandable bellows 18 is secured air-tightly to upper plate16 by bolts 19 and 20, and a "lower expandable bellows 21 is secured air-tightly to lower plate 17 by similar bolts 22 and 23. Bellows 18 and 21 are both secured air-tightly to support structure 11 by action of circular pressure plates 24 and 25 in cooperation with bolts 26 and 27. A vertical bore 28" nects with a second bore 31 also formed in support structure 11, A rubberized or a synthetic plastic pressure Patented Mar. 29, 1960 A second conduit means is slidably seal 32 capable of withstanding the corrosive nature of the wash is pressed onto or otherwise secured to the upper end of conduit 13. Bellows 18 and 21 are shielded from' exposure to the wash by a cylindrical shield mem ber 33 secured to plate 16 by bolts 19' and20; a" second cylindrical shield member 34 secured to pressure plate 24 by bolts 26 and 27 and a third cylindrical shield member 35 secured to pressure plate 25' by bolts 26 and 27.

Bellows 18 and 21 are filled with a fluid 36 such as ordinary motor oil for lubricating sleeve bearings 14 and 15. A C-shaped arm 37 is connected to support structure 11 and adapted for suspending a cathode-ray tube envelope 38 in a vertical position with the neck portion thereof extending downwardly as viewed. A second arm 39 is also connected to frame 11 and supports a tube neck guide structure 40 connected to a plate 41. A second conduit member 42 extending "at least into the neck portion of tube 38- is supported by a second rubberized or synthetic plastic seal 43 connected to plate 41 in any suitable manner. The wash solution, as injected into the envelope of tube' 38, is drained therefrom through the neck portion thereof, through openings 44' formed in plate member 41, and" into a work tank 45 secured to support structure 11. Wash solution is then drained from tank 45, through a drainpipe 46, and into a reservoir of wash solution 47. Wash solution from reservoir 47 is removed through a suction pipe 48 by a pump 49 and then supplied'underl ously retracted during expansion of upper bellows 18; In addition, as lever 61 is rotated 90 degrees clockwise, switch 54 is closed thereby to energize pump 49 to supply a high pressure stream of washing fluid through pressure line 50 and conduits 13 and 42, and this jet of washing fluid is directed onto only the internal face of tube envelope 38.

Electrical power is supplied to pump 49 from any suit able source such as the main service lines (not shown) through a switch 54 and conductors 55 and 56. A suitable fluid under pressure, which may be either hydraulic fiuid or compressed air, is supplied to valve 51 by a suitable compressor 57 through feed line 58 and is exhausted therefrom through exhaust line 59. If a hydraulic fluid is used as the actuating medium instead of air, then exhaust line 59 is returned to a reservoir not shown. A rotatable armature 60, actuatable by a lever 61, is contained within valve 51 for selectively connecting pressure line 58 and exhaust line 59 to feed lines 52 and 53 respectively or vice versa.

In operation a cathode-ray tube envelope is inserted into holder 37 with conduit 42 extending into at least the neck portion of the tube envelope and preferably into the bulb portion above reference line 62. With the rotor 60 of valve 51 in the position shown in full outline, pressurized fluid (preferably compressed air) from line 58 is ported through valve 51, into connecting feed line 53, through bores 31 and 30 and thus expands lower bellows 21 to create a downward force against plate 17. As conduit 13 is integrally connected to plate 17, con-- duit 13 is forced downward to a retracted position as by lever 61 to a position as shown in dotted outline 63,

pressure line 58 is connected to feed line 52 and exhaust line 59 is simultaneously connected to feed line 53, Inthis condition, pressurized fluid from source 57 is ported through feed line 58, into valve 51, through feed line 52, and through bores 29 and 28 to expand upper bellows 18 and thus create a lifting force on upper plate 16.- As plate 16 is also integrally connected to conduit 13,- conduit 13 is forced upward to engage pressure seals 32 and 43 thus connecting conduits 13 and 42. As feed line 53 is simultaneously connected to exhaust line 59, the fluid in lower bellows 21 is vented to atmospheric A washing apparatus such as shown and described has several advantages over prior attempts to devise a highly eflicient apparatus for washing the internal surfaces of cathode-ray tube envelopes; One of the outstanding advantages is that by injecting a high-velocity stream of washing solution through a guide conduit such as conduit 42, the high-velbcity stream impinges only on the face of tube envelope 38, thus preventing any interference of the solution draining from the tube with the incoming washing stream and greatly enhancing thewashing efliciencyof the apparatus. Again, as the washing fluid is injected into the bulb under pressure, a resultant pressure is created within the envelope to increase the speed with which the washing solution drains therefrom, greatly decreasing the time for the completion of a washing operation. It has been found that utilizing an apparatus such as that shown, it is not at all uncommon that less than 5% of the total tube rejections after screening are due to improper washing as contrasted to 50% with previous apparatus. Since lubricating fluid 36 is completely enclosed within bellows 18 and 21, abrasive materials formed during the washing processes do not interfere at all with the washing operation. To insure long life of the apparatus it is preferred that all exposed parts be composed of a corrosion-resistant metal such as a nickel-iron alloy of the type known as Hastelloy C as manufactured by Haynes Stellite Company. Even though bellows 18 and 21 are shielded from the wash solution, they may nevertheless be exposed to a certain amount of wash solution due to splashing, leakage, etc. and therefore it is further preferred that bellows 18 and 21 be composed of a corrosion-resistant material such as the synthetic plastic manufactured by E. I. du Pont de Nemours and Co. under the name of Teflon.

Although a single station of washing operation is shown, it is readily apparent to those skilled in the art that'the apparatus shown and described is readily adaptable to incorporation in a multi-station automatic washing'machine by utilizing well known and understood automation techniques.

While a particular embodiment of the invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

I claim:

1. Apparatus for washing the internal surface of a cathode-ray tube envelope comprising: means for supporting said envelope in an inverted position; first conduit means having one end thereof secured to said supporting means and the opposite end thereof adapted to extend into at least the neck portion of said envelope; second conduit means slidably carried by said supporting means; reversible fluid-operable actuating means including a bellows fixed to said supporting means for reciprocating said second conduit means to selectively engage and disengage one end of said second conduit means with the supported end of said first conduit means; means for injecting a washing fluid under pressure through said second conduit means; fluid pressure means operatively connected to said bellows means; and valve means for selectively controlling said fluid pressure means and said injecting means to actuate said injecting means only upon operation of said actuating means to effect engagement pressure to permit the lower bellows to be sirnultaneof said first and second conduit means.

2. Apparatus in accordance with claim 1 wherein a duit for washing solution secured to said supporting means and projecting into the neck of a supported tube envelope; a second conduit for washing solution shiftably supported for. movement intoand away from coupling relation to said first conduit; fluid operable actuating'means, including a support and bellows mounted on said support, for moving said second conduit into said coupling relationjwith said first conduit; a tank mounted on said support and surrounding said bellows for receiving the washing solution drainage expelled from. said envelope neck; and telescoping shield members enclosing said bellows and carried by said support and said bellows for preventing expelled drainage from splashin 1 gainst said bellows. K

References Cited in the fileof this patent UNITED STATES PATENTS! 2,176,845 Temple Oct. 17,1939 2,549,837 Merritt Apr. 24, 1951' 2,561,631 Negri July 24, 1951 2,604,896 Cozzoli July 29, 19,52

McKenzie Sept. 18, 

